chore: ckb version tweaks (nervosnetwork#449)

- rerun build.rs to get latest version info when any file has changed.
- include pre version.

build.rs

@@ -1,6 +1,4 @@
 fn main() {
-    // Don't rebuild even if nothing changed
-    println!("cargo:rerun-if-changed=build.rs");
     // forward git repo hashes we build at
     println!(
         "cargo:rustc-env=COMMIT_DESCRIBE={}",

util/build-info/src/lib.rs

@@ -12,6 +12,14 @@ macro_rules! get_version {
         let patch = env!("CARGO_PKG_VERSION_PATCH")
             .parse::<u16>()
             .expect("CARGO_PKG_VERSION_PATCH parse success");
+        let dash_pre = {
+            let pre = env!("CARGO_PKG_VERSION_PRE");
+            if pre == "" {
+                pre.to_string()
+            } else {
+                "-".to_string() + pre
+            }
+        };
 
         let host_compiler = $crate::get_channel();
         let commit_describe = option_env!("COMMIT_DESCRIBE").map(|s| s.to_string());
@@ -20,6 +28,7 @@ macro_rules! get_version {
             major,
             minor,
             patch,
+            dash_pre,
             host_compiler,
             commit_describe,
             commit_date,
@@ -28,18 +37,23 @@ macro_rules! get_version {
 }
 
 // some code taken and adapted from RLS and cargo
+#[derive(Debug)]
 pub struct Version {
     pub major: u8,
     pub minor: u8,
     pub patch: u16,
+    pub dash_pre: String,
     pub host_compiler: Option<String>,
     pub commit_describe: Option<String>,
     pub commit_date: Option<String>,
 }
 
 impl Version {
     pub fn short(&self) -> String {
-        format!("{}.{}.{}", self.major, self.minor, self.patch)
+        format!(
+            "{}.{}.{}{}",
+            self.major, self.minor, self.patch, self.dash_pre
+        )
     }
 
     pub fn long(&self) -> String {
@@ -52,10 +66,11 @@ impl std::fmt::Display for Version {
         if self.commit_describe.is_some() {
             write!(
                 f,
-                "{}.{}.{} ({} {})",
+                "{}.{}.{}{} ({} {})",
                 self.major,
                 self.minor,
                 self.patch,
+                self.dash_pre,
                 self.commit_describe.clone().unwrap_or_default().trim(),
                 self.commit_date.clone().unwrap_or_default().trim(),
             )?;